This invention relates to a screen for a watercraft jet propulsion unit and more particularly to an improved inlet screen construction that can be conveniently opened for servicing of the water inlet portion of a jet propulsion unit.
Jet propelled watercraft have a number of advantages. In addition to providing a propulsion system that has a number of advantages over propeller type watercraft, a jet propelled watercraft can have a very neat appearance if the jet propulsion unit is positioned at least in substantial portion within a tunnel on the under side of the watercraft hull. However, there are times when it is desirable to access the water inlet opening of the jet propulsion unit for servicing.
One of the advantages of jet propulsion units is that they permit the watercraft to be operated in very shallow bodies of water. However, when operating in such shallow bodies of water, it is possible to ingest seaweed and other foreign materials into the jet propulsion unit which must be removed to preclude clogging of the unit.
It has also been proposed to provide some form of inlet screen across the opening of the jet propulsion unit so as to preclude large articles from being drawn into the jet propulsion unit and damaging the impeller and its internal components. Of course, if such a screen is employed then it must be removed in order to clear smaller articles which may have entered past the screen and become lodged in the water inlet opening of the jet propulsion unit.
In order to facilitate the servicing of jet propulsion units and particularly those which are mounted in or beneath the hull of the watercraft, it has been proposed to mount either the entire jet propulsion unit or portions of it for movement between their normal driving position and a service position. In the service position, the water inlet opening may be rotated to a raised position for offering access through an access opening in the hull which defines the tunnel in which the jet propulsion unit is contained. The co-pending application of Noboru Kobayashi entitled, "Water Jet Propulsion Unit," Ser. No. 735,154 filed Jul. 22, 1991, which is a continuation of his application Ser. No. 489,361, filed Mar. 6, 1991 and now abandoned, which applications are assigned to the assignee hereof, shows a number of jet propelled watercraft wherein the water inlet opening may be accessed for servicing.
Again, with this type of jet propulsion unit it is also desirable to provide a screen across the inlet opening to exclude large foreign articles. However, the screen must be removed in order to permit servicing of the inlet opening and the removal of foreign objects therefrom. This gives rise to some disadvantages with the prior art type of constructions.
It is, therefore, a principal object of this invention to provide an improved screen arrangement for the water inlet opening of a jet propulsion unit which can be easily opened for servicing and which requires no complex latching arrangement.
It is a further object of this invention to provide an improved water jet propulsion unit for a watercraft having a screen over its water inlet portion which can be easily opened for servicing.